Cellulose Spherical Microbeads Interfacially-controlled by Hard Inorganic Nano-Particles Using Viscose Phase Separation Method and Their Applications to Abrasive Materials

We prepared various types of cellulose/inorganic particle- composite spherical microbeads. These were hybridized with SiC, Al2O3 and diamond particles by a one-step phase separation method using a viscose and a sodium polyacrylate aqueous solution, respectively, as abrasives to lap silicon wafer. It was found that the differences relative to the electrophoretic mobility of inorganic particles in viscose influenced the distribution of particles that were contained in the obtained microspheres. The cellulose/SiC or diamond particles composite spherical microbeads were covered with SiC (mean particle diameter: 1 μm) or diamond particles (mean particle diameter: 200 nm or 600 nm), respectively, since their distributions of electrophoretic mobility were narrow in pH 13 aqueous solution under sphering condition. In addition the lapping with the cellulose/diamond-200 nm composite spherical microbeads provided the more favorable profile to surfaces of silicon wafers than diamond alone. A novel lapping method, was developed in which cellulose/diamond composite spherical microbeads were introduced to accomplish high abrasive performance.